<template>
  <a-cascader
    v-model:value="state"
    :options="options"
    :load-data="loadData"
    change-on-select
    @change="handleChange"
    :displayRender="handleRenderDisplay"
  >
    <template #suffixIcon v-if="loading">
      <LoadingOutlined spin />
    </template>
    <template #notFoundContent v-if="loading">
      <span>
        <LoadingOutlined spin class="mr-1" />
        {{ t("component.form.apiSelectNotFound") }}
      </span>
    </template>
  </a-cascader>
</template>
<script lang="ts" setup>
  import { PropType, ref, unref, watch, watchEffect } from "vue";
  import { Cascader as ACascader } from "ant-design-vue";
  import { propTypes } from "/@/utils/PropTypes";
  import { isFunction } from "/@/utils/Is";
  import { get, omit } from "lodash-es";
  import { useRuleFormItem } from "/@/hooks/component/UseFormItem";
  import { LoadingOutlined } from "@ant-design/icons-vue";
  import { useI18n } from "/@/hooks/web/UseI18n";
  import { ValueType } from "ant-design-vue/es/vc-cascader/Cascader";

  interface Option {
    value: string;
    label: string;
    loading?: boolean;
    isLeaf?: boolean;
    children?: Option[];
  }
  defineOptions({ name: "ApiCascader" });
  const props = defineProps({
    value: {
      type: Object as PropType<ValueType>
    },
    api: {
      type: Function as PropType<(arg?: Recordable) => Promise<Option[]>>,
      default: null
    },
    numberToString: propTypes.bool,
    resultField: propTypes.string.def(""),
    labelField: propTypes.string.def("label"),
    valueField: propTypes.string.def("value"),
    childrenField: propTypes.string.def("children"),
    asyncFetchParamKey: propTypes.string.def("parentCode"),
    immediate: propTypes.bool.def(true),
    // init fetch params
    initFetchParams: {
      type: Object as PropType<Recordable>,
      default: () => ({})
    },
    // 是否有下级，默认是
    isLeaf: {
      type: Function as PropType<(arg: Recordable) => boolean>,
      default: null
    },
    displayRenderArray: {
      type: Array
    }
  });
  const emit = defineEmits(["change", "defaultChange"]);
  const apiData = ref<any[]>([]);
  const options = ref<Option[]>([]);
  const loading = ref<boolean>(false);
  const emitData = ref<any[]>([]);
  const isFirstLoad = ref(true);
  const { t } = useI18n();
  // Embedded in the form, just use the hook binding to perform form verification
  const [state] = useRuleFormItem(props, "value", "change", emitData);

  watch(
    apiData,
    (data) => {
      const opts = generatorOptions(data);
      options.value = opts;
    },
    { deep: true }
  );

  function generatorOptions(options: any[]): Option[] {
    const { labelField, valueField, numberToString, childrenField, isLeaf } = props;
    return options.reduce((prev, next: Recordable) => {
      if (next) {
        const value = next[valueField];
        const item = {
          ...omit(next, [labelField, valueField]),
          label: next[labelField],
          value: numberToString ? `${value}` : value,
          isLeaf: isLeaf && typeof isLeaf === "function" ? isLeaf(next) : false
        };
        const children = Reflect.get(next, childrenField);
        if (children) {
          Reflect.set(item, childrenField, generatorOptions(children));
        }
        prev.push(item);
      }
      return prev;
    }, [] as Option[]);
  }

  async function initialFetch() {
    const api = props.api;
    if (!api || !isFunction(api)) return;
    apiData.value = [];
    loading.value = true;
    try {
      const res = await api(props.initFetchParams);
      if (Array.isArray(res)) {
        apiData.value = res;
        return;
      }
      if (props.resultField) {
        apiData.value = get(res, props.resultField) || [];
      }
    } catch (error) {
      console.warn(error);
    } finally {
      loading.value = false;
    }
  }

  async function loadData(selectedOptions: Option[]) {
    const targetOption = selectedOptions[selectedOptions.length - 1];
    targetOption.loading = true;

    const api = props.api;
    if (!api || !isFunction(api)) return;
    try {
      const res = await api({
        [props.asyncFetchParamKey]: Reflect.get(targetOption, "value")
      });
      if (Array.isArray(res)) {
        targetOption.children = generatorOptions(res);
        return;
      }
      if (props.resultField) {
        targetOption.children = generatorOptions(get(res, props.resultField) || []);
      }
    } catch (e) {
      console.error(e);
    } finally {
      targetOption.loading = false;
    }
  }

  watchEffect(() => {
    props.immediate && initialFetch();
  });

  watch(
    () => props.initFetchParams,
    () => {
      !unref(isFirstLoad) && initialFetch();
    },
    { deep: true }
  );

  function handleChange(keys, args) {
    emitData.value = keys;
    emit("defaultChange", keys, args);
  }

  function handleRenderDisplay({ labels, selectedOptions }) {
    if (unref(emitData).length === selectedOptions.length) {
      return labels.join(" / ");
    }
    if (props.displayRenderArray) {
      return props.displayRenderArray.join(" / ");
    }
    return "";
  }
</script>
